[37.09] IBIS: Instrument Description and First Results

F. Cavallini (INAF/Osservatorio Astrofisico di Arcetri), IBIS Team

In June 2003, the Inferometric Bidimensional Spectrometer
(IBIS) was installed at the Dunn Solar Telescope at
Sacramento Peak Observatory. This new instrument uses two
Fabry-Perot interferometers to permit the detailed sampling
(30-40 mÅFWHM) of solar spectral lines over an 80
arcsecond diameter field of view in the range 5800-8600 Å.
IBIS operates in combination with the NSO adaptive optics
system, allowing it to achieve diffraction-limited images,
while being able to scan through an entire spectral line in
5-10 seconds. The instrument design placed a premium on
reducing parasitic spectral light and maintaining a stable
and uniform spectral transmission profile across the field
of view.

We present the operational characteristics of the instrument
as determined from laboratory calibrations as well as tests
performed during the initial observing runs with the
instrument. We provide examples of the datasets obtained
during these first observing runs and some preliminary
results gleaned from these data. We also indicate some of
the scientific programs for which this instrument is ideally
suited.